1. Field of the Invention
The present invention relates generally to circuit breakers and, more particularly, to circuit breakers employing one or more alarm switches and/or auxiliary switches that are operated by the operating mechanism of the circuit breaker. Specifically, the invention relates to a securing member that resists movement of a switch actuation lever toward a crossbar of an operating mechanism to avoid the actuation lever from becoming entangled with the operating mechanism.
2. Description of the Related Art
As is understood in the relevant art, circuit breakers are used for numerous purposes in power distribution systems. Among such purposes is the interruption of current in a protected system during certain specified overcurrent and under-voltage conditions, as well as other conditions. In multi-pole circuit breakers, each pole includes a stationary contact and a movable contact, the movable contact being pivotable into and out of electrical engagement with the stationary contact.
The movable contacts typically are commonly operatively mounted on an operating mechanism that simultaneously moves all of the movable contacts out of electrical engagement with the stationary contacts in the event of a specified overcurrent or under-voltage condition or other condition. The operating mechanism typically includes a rotatable crossbar extending between the poles to which the movable contacts are operatively mounted. Rotation of the crossbar causes the movable contacts of all of the poles to be simultaneously pivoted into and out of electrical engagement with the stationary contacts as needed.
Inasmuch as the electrical disengagement of the movable contacts from the stationary contacts results in an interruption of current through the circuit breaker, it is known in the art to provide one or more switches that are mechanically operated by the crossbar or other components of the operating mechanism or other mechanisms and that are operatively connected with alarm bells, warning lights, and other devices that are calculated to inform a technician that the circuit breaker is in an interrupted or off condition. Such switches are components in a switch assembly that is mountable within the circuit breaker and often include an alarm switch that is operatively connected with the cradle or handle of the operating mechanism to detect a tripped state of the circuit breaker and one or more auxiliary switches that are operatively connected with the crossbar and indicate the open or closed state of the separable contacts. In such applications, the switches usually each include an actuation lever in the form of a tang of spring steel or other material that is connected at an attachment end thereof with the switch housing and that protrudes outwardly therefrom. The crossbar includes one or more eccentric camming surfaces which, upon rotation of the crossbar, depress the actuation levers of the switches. Depression of the actuation levers by the camming surfaces causes the actuation levers to each depress a plunger that actuates the electrical contacts within the switch that operate the alarm devices connected therewith.
While such switch assemblies have been effective for many of their intended purposes, such switch assemblies have not, however, been without limitation. It is known that the actuation levers of the auxiliary switches are slidably disposed against and are depressed by the camming surfaces of the crossbar during rotation of the crossbar. Moreover, it is known that rotation of the crossbar preferably occurs rapidly under the specified conditions to quickly separate the movable contacts. Some circuit breakers are configured such that during the aforementioned rotation, movement of the camming surfaces is in a direction from the free ends of the actuation levers toward the attachment ends thereof. In such configurations, it has occasionally been observed that during rapid movement of the camming surfaces, one or more of the actuation levers can undesirably be frictionally carried with the camming surfaces instead sliding thereon. Under such circumstances, the affected actuation levers are pulled from one side of the crossbar to an opposed side of the crossbar, in which case the actuation levers are pulled away from operative contact with the plungers. Such a condition renders the switches become inoperable despite the tripped condition of the circuit breaker. Such a situation is undesirable inasmuch as the alarm devices with which the switches are connected will not operate when the circuit breaker is in the interrupted or off condition, which can, in turn, prolong the time during which the interrupted condition of the circuit breaker goes undetected by a technician. Moreover, the available space within a circuit breaker is extremely limited, and thus any device that is intended to resist such mis-actuation of the actuation levers must be tailored to fit within such a confined space. It is thus desired to provide a device that is compact and that resists entanglement of the actuation levers of auxiliary switches with the operating mechanism of a circuit breaker.
In view of the foregoing, a securing member is provided for use in conjunction with a switch assembly of a circuit breaker. The securing member includes a fastener and a support post mounted on and extending outwardly from the fastener. The switch assembly includes a bracket, an alarm switch, and at least a first auxiliary switch, with the securing member being mounted on the bracket. The securing member both mounts the alarm switch on the bracket and underlies the actuation levers of the auxiliary switches to resist movement of the actuation levers beyond a given position, which thus resists the actuation levers from becoming entangled in the operating mechanism of the circuit breaker. The fastener includes a flange and an attachment structure, with the flange being disposed against one side of the bracket, and with the attachment structure extending through a mounting hole formed in the bracket. The attachment structure is configured to mount the alarm switch on the bracket. The support post extends outwardly from the side of the flange opposite the attachment structure in a direction generally away from the alarm switch.
An aspect of the present invention is to provide an improvement to a circuit breaker of the type including an operating mechanism and a switch assembly, the switch assembly including a bracket, a first switch, and a second switch, the second switch including a housing and an actuation lever, the actuation lever extending at least partially alongside and being movable with respect to the housing, the first switch being mounted on the bracket with a fastener, in which the general nature of the improvement can be stated as including a support post mounted on the fastener, the support post being disposed adjacent the actuation lever and being structured to resist movement of the actuation lever farther away from the housing than a given position.
Another objective of the present invention is to provide a securing member for mounting a first switch to a bracket, the bracket being formed with at least a first mounting hole and carrying a second switch, the general nature of which can be stated as including a fastener structured to be at least partially received in the at least first mounting hole and a support post mounted on and extending outwardly from the fastener, the support post being structured to be disposed adjacent the second switch.
Still another aspect of the present invention is to provide a method of resisting movement of a first actuation lever of a first switch farther away from a first housing of the first switch than a first given position, the general nature of which can be stated as including the steps of mounting a second switch to a bracket with a fastener, providing a support post extending from the fastener, the support post being disposed alongside the first actuation lever, and abutting the first actuation lever against the support post when the first actuation lever is in the first given position.